Climate forcing research

satellite image showing smoke over Gulf of Mexico, Yucatan PeninsulaGreenhouse gases—such as water vapor, carbon dioxide, methane, chlorofluorocarbons (CFCs), and nitrous oxide—trap heat radiating from our planet's surface. To better understand just how human activities are changing our planet's radiative energy balance, CIRES scientists measure the heat-absorbing properties and lifetimes of greenhouse gases and ozone. Ozone plays a particularly important role in controlling the overall chemistry of the atmosphere and the lifetimes of chemically active gases like methane.

We also investigate how the chemical composition of aerosols may influence the earth's temperature. By examining how different aerosols reflect the sun's radiation, we're able to estimate how they affect the heat balance of the atmosphere. In addition, aerosols appear to affect the planet's temperature indirectly by acting as nuclei for water condensation, facilitating cloud formation. Clouds, depending on their height and thickness, can either deflect radiation or trap it. Improving our understanding of the role of aerosols in influencing cloud formation and cloud radiative properties will vastly improve global climate modeling forecasts.